A computer program was developed to derive spectral parameters from assembled hydrologic data. Parameters from cross spectral analysis include gain, phase, and coherence. A supplementary computer program analyzes data for significant harmonics in accordance with principles of a generalized Fourier-harmonic rationale. Spectral characteristics of precipitation reveal significant peaks on annual and semi-annual cycles. Peaks in streamflow spectral description are less marked. Close agreement between characteristics is evidenced for large basins, whereas small basins reflect noticeable divergence. This supports the observation that small drainage basins are more sensitive than large basins in responding to precipitation in terms of water yield. Generalized harmonic analyses for precipitation and streamflow reveals that time-variation of precipitation is significantly concentrated in first three out of six harmonics, whereas streamflow description would necessitate five out of six harmonics. (Author)